1. Field of the Invention
The present invention concerns an apparatus for making edible articles by immersing plungers into chocolate-like mass deposited directly onto a conveyor web.
2. Background of the Invention
Generally, chocolate-like masses are suspensions of non-fat particles such as sugar, milk powders and cocoa solids mixed up with a liquid fat constituent. Often the fat phase comprises genuine cocoa butter of until around 30%, but may comprise substitutes as well. Such substitutes can be in the form of other types of fat-containing oils. Chocolate types where the cocoa butter has been replaced wholly or partly by other fats are often named commercially as compound chocolate, in which the cocoa butter has been replaced by palm-kernel oil. Mass made of 100% fat in the form of cocoa butter or the like as compound is also possible.
However, for the chocolate-like mass according to the present invention it is decisive, that whether the fat phase constitutes of genuine cocoa butter or substitutes therefore, that the fat phase is capable of crystallizing into stable crystal types, such as the xcex2-crystals developing in genuine cocoa butter when the mass solidifies.
The chocolate-like mass is brought to a tempered, liquid state and then deposited directly onto a conveyor web. Optionally, the conveyor web may then be shaken for obtaining a more even distribution of the chocolate mass.
By the tempering process the mass is brought to around 40-50xc2x0 C., where after it is being cooled to around 25-34xc2x0 C. so that crystallisation is initiated. Then the mass is reheated around 0.5-2.0xc2x0 C. for re-melting most of the in-stable crystals in the mass, however preserving a content of stable xcex2-crystals which melts at a higher temperature than the in-stable crystals. The stable crystals are preserved in the mass ready for depositing in an amount of typically 0.01%-5%, preferably in an amount of 0.1%-2%. The stable crystals could preferably be of the xcex2V or xcex2IV type.
After the edible articles made are solidified, they could be filled with a centre mass of a creamy or liquid food material, which differs from that of the article material. The centre mass could be an alcohol containing mass, a sugar containing mass or a creamy fondant mass, simply any of the centre masses known to the chocolate industry. Finally, a chocolate covering layer may be deposited for closing the centre mass off thereby creating a kind of xe2x80x9cpraline-likexe2x80x9d article. If the edible article made by the invention is flat or plate-shaped such as a tablet, a centre in the form of a bisquit could be arranged as well.
WO 98/30111 (Mars) discloses embossing of details on top of enrobed products. A bar-shaped centre is arranged on a supporting surface and enrobed with chocolate mass before embossing. The disclosure is silent about depositing chocolate directly on a conveyor web before embossing as the disclosure exclusively deals with enrobed products. The disclosure teaches low temperatures of the embossing surfaces typically being below 0xc2x0 C. and that ice builds up on the embossing surfaces. The ice melts in contact with the chocolate working as a lubricant, which secures separation from the covering layer when the embossing device is retracted therefrom. The disclosure is silent about how to keep the articles staying on the supporting surface when the embossing plungers are retracted.
The inventive apparatus makes edible articles of chocolate-like mass, in particular chocolate mass, being tempered and deposited directly on a conveyor web. A holding and cooling device carrying plungers with pressing surfaces is arranged above the conveyor web and is movable up- and down in relation thereto. The holding device with plungers as well as the underlying part of the conveyer web are arranged in a housing connected to air drying means adapted to supply dry air into the housing.
The pressing surfaces of the plungers are kept dry and free from any lubricant or moisture from the air. The conveyor web surfaces are kept free from lubricant and moisture as well. Thereby it is possible to make chocolate articles directly on a conveyor web without the use of any lubricants which could contaminate the articles.
The plungers having dry pressing surfaces onto which no lubricant is applied are immersed into contact with deformable, non-solidified tempered chocolate deposited directly in small lumps on a conveyor web and thereby being pressed into the shape of an article. The temperature of the pressing surfaces is kept below the solidification temperature of the chocolate mass during the pressing, whereafter the plungers are retracted from the edible articles.
So necessary for the plunger to be capable of being retracted from the chocolate without deforming the contacted surfaces of the article is, that the outer part or surface xe2x80x9cskinxe2x80x9d of the chocolate layer has solidified and thereby contracted slightly. The pressing surfaces are high gloss surfaces.
A predetermined geometry of a chocolate article can be obtained directly on a conveyor web from a deposited lump of chocolate without the use of any separate moulds or mould plates or any bar-shaped centre or the like.
When being deformed by the pressing surfaces of the plungers the ready made surfaces of the chocolate articles are simply an identical print of the geometry of the plunger pressing surfaces. Deleterious effects to the chocolate caused by remains of lubricant, whether it be water, gelatine or any other possible receipt is completely avoided. Furthermore is contamination of the plungers and the edible chocolate articles with lubricant remains avoided. Remains having a water content is certainly suspected to give rise to bacteria growth such as in the dangerous salmonella form.
The chocolate rapidly solidifies under crystallisation from its surface in contact with the pressing surfaces of the plunger and inwardly through the chocolate layer. By being forced into contact with the colder pressing surfaces of the plunger, the tempered chocolate instantly solidifies and contracts slightly at its part in contact with the pressing surfaces whereby it releases. Decisive is here, that the tempered chocolate contains stable crystals, which makes the chocolate mass contract just slightly when it solidifies in contact with a continuously cooled surface. A solidified outer xe2x80x9cskinxe2x80x9d is created on the chocolate in contact with the pressing surfaces when the chocolate solidifies and contracts slightly, and this is sufficient for the chocolate to release from the plunger surface where after the plunger can be retracted. The pressing surfaces are high gloss surfaces so that diminishing friction is created with the chocolate mass when it contracts slightly during contraction. The remaining or inner part of the chocolate layer then doesn""t need to be solidified when the plunger is retracted from its contact with the chocolate. The solidified xe2x80x9cskinxe2x80x9d of the chocolate layer secures a geometrical stable geometry of the article though heat remains inside the chocolate mass when the plunger is retracted from contact.
Thereby it has though become possible to make chocolate articles directly on a conveyor web by use of plungers and without applying any lubricant, yet still moulding the articles with the complete geometry without any surplus chocolate to be re-circulated. The production line then becomes very simple as it is free from any moulds or mould plates. Any de-moulding, removal or knocking out of articles from moulds becomes superfluous as the articles by the inventive technique simply stays on the conveyor web in the position they were pressed being transported on to possible further modification, such as the depositing of centre mass in pressed cavities of the article or the like.
When the plungers have been retracted the surfaces of the chocolate articles are completely dry and free from any remains of lubricant. Whether the articles made are to be eaten with visible surfaces made by the plungers or are to be filled with centre mass and closed of, remains of lubricant is no matter of pure appearance. Lubricant remains and especially when having the slightest water content dissolves the chocolate surface and gives rise to xe2x80x9cfat-bloomxe2x80x9d in the chocolate, bad taste and is the perfect basis for bacteria growth, which makes people sick. There is plenty of accidents in chocolate making history by which contamination of a centre mass in a closed chocolate article has been the coarse of swelling, so that the filled article more or less xe2x80x9cexplodedxe2x80x9d. Several accidents with salmonella contamination of chocolate is known as well.
No moisture is created on the pressing surfaces and pick up or build up of chocolate particles on the pressing surfaces with time is avoided as well as contamination of the chocolate with dew.
However, especially when maintaining cold surface temperatures of the pressing surfaces, i.e. such as below +5xc2x0 C., a secure precaution for avoiding creation of dew at the pressing and forming surfaces is to keep the dew point temperature of the air surrounding the surfaces below the temperature of the surfaces in question.
When the temperature of the pressing surfaces are kept below 0xc2x0 C. in contact with the chocolate mass during pressing, an especially strong article wall against leaking out of a subsequently deposited filling is secured. The tempered mass is caught mostly in its xe2x80x9cnucleixe2x80x9d form of the desirable crystals directly at the non-lubricated pressing surfaces as the crystals are not given any really time to solidify by growth due to the chill being forced by the non-lubricated and cold pressing surfaces of the plungers into the chocolate. Thereby, the surface layer or xe2x80x9cskinxe2x80x9d of the tempered chocolate shell instantly contracts slightly and becomes hard when it releases the surface of the plunger. An increase around 25-35% in shell strength of the inner surface has been observed. Such an increase in strength is of great importance when the article is subsequently filled with a centre mass which off course must not leak out of the chocolate article before it being eaten.
When the plungers are retracted before the articles have solidified completely, the chill forced from the inside does not reach all the way through the layer before the plungers are retracted. Though the bottoms of the articles in contact with the conveyor web have solidified slightly in the outer xe2x80x9cskinxe2x80x9d simultaneously with the forced solidification from the pressing surfaces of the articles in contact with the plungers, heat still remains in the inside of the articles when the plungers are retracted. The inner of the chocolate articles are more or less xe2x80x9cleather-likexe2x80x9d when the plungers are retracted.
However, care should be taken so that the chill is limited and so that it is secured, that the rapid cooling from the pressing surfaces doesn""t reach all the way through the articles whatever the thickness thereof may be. If it does it may create cracks in the chocolate, especially at xe2x80x9csharpxe2x80x9d corners, etc. or at parts where the thickness varies. The combination of the temperature of the pressing surfaces and the immersion time thereof in contact with the chocolate determines the actual amount of chill taken up by the chocolate mass. Obviously, the immersion time has to be reduced when the article thickness is smaller when keeping the temperature of the pressing surfaces essentially constant.
The thickness of the chocolate edible articles manufactured is typically between 1 and 5 mm. It has been observed, that for reaching the above effect of remaining heat inside the article walls, the immersion time should be less than 1 second for a 1 mm thick wall, less than 2 seconds for a 2 mm thick wall and less than 3 seconds for a 3 mm thick wall, less than 4 seconds for a 4 mm thick wall and less than 5 seconds for a 5 mm thick wall when the temperature of the pressing surfaces was constantly kept around xe2x88x9220xc2x0 C. When the temperature of the pressing surfaces was kept around xe2x88x925xc2x0 C. the immersion periods should approximately be less than 1.5 seconds, 3 seconds, 4 seconds, 6 seconds and 8 seconds for the 1 mm, 2 mm, 3 mm, 4 mm and 5 m wall thickness. However these guidelines are approximately and not exact for all geometries. However, it was observed, that especially flat articles could be chilled through without any deterioration or cracks appearing when the geometry of the articles were simple such as for a flat-shaped, planar article.
Though the pressing surfaces of the plungers have released from any sticking with the chocolate the chosen geometry of the surfaces may still create surface suction or friction when the plungers are retracted, which overcomes the gravitational forces on the articles and the articles may be lifted up from the support.
However, for several reasons and especially for obtaining a xe2x80x9chardxe2x80x9d and strong bottom of the articles it is preferable to keep the temperature of the conveyor web below the solidification temperature of the chocolate mass. When doing so, the secure retaining of the articles on the conveyor web is ensured when the holding device of the apparatus carries a closure plate, which is movable in relation to the plungers, surrounds the periphery of each plunger and is adapted to overlap at least part of the rim of the pressed articles. The temperature of the forming surfaces of the closure plate is kept below the solidification temperature of the tempered chocolate mass.
Then the complete geometry of the articles are determined by the pressing surfaces of the plungers, by the forming surfaces of the closure plate and by the planar conveyor web surface.
The condition of the tempered chocolate mass is chosen so that when deposited in small lumps on the conveyor web it doesn""t xe2x80x9crunxe2x80x9d over the conveyor surface due to being to xe2x80x9cliquidxe2x80x9d or high viscous. On the other hand the deposited chocolate shall also be deformable, meaning that it must not have solidified to such an extent that it becomes impossible to deform it without cracks and incomplete filling of the enclosure and incomplete contact with the pressing and forming surfaces.
After being deposited the lumps are positioned under the plungers and the holding device carrying the plungers and the closure plate is lowered. The closure plate comes to contact with the conveyor web and each lump is surrounded by forming surfaces and thereby securely bordered by these on the conveyor web. By the further lowering of the holding device the plungers come to contact with the mass so the pressing surfaces forces the mass to complete distribution over the pressing surfaces, the forming surfaces and the enclosed parts of the conveyor web surfaces.
During the initial retraction of the holding device which may only be part of a millimeter or a few millimeter, the plungers are lifted free from the chocolate article, however the closure plate remains in contact with the conveyor web surface so that the part of the forming surfaces overlapping the articles secures that the articles are kept on the conveyor web.
The closure plate may be influenced by a force from above, which secures that the plate is fully in contact with the conveyor web, especially during the initial part of the retraction of the holding device when the plungers are lifted. The force against the holding plate may be activated by pneumatic or hydraulic means or simply by compressible spring means.
When the holding device comprises cooling channels through which cooling liquid is circulated, the plungers and the closure plate is influenced by the cooling of the circulating liquid. By controlling the temperature of the liquid the temperatures of the pressing surfaces and the forming surfaces can be controlled to below the solidification temperature of the tempered chocolate mass in question.
When the plungers are independently suspended to the holding device so that they are adapted to move independently of each other, a complete filling out of the pressing enclosures and thereby contact of the mass with any pressing and forming surfaces are ensured whatever the deviations in the volume of the deposited, individual lumps of chocolate mass may be. Deviations in the volume of the individual deposited lumps of tempered chocolate is always present, and due to the individual suspension of the plungers, each plunger will simply be pressed more or less down into the chocolate mass in accordance with actual volume thereof so that complete filing of the enclosures are secured. The individual articles then varies slightly in height, however here we are talking about dimensions such as fractions of a millimeter, which is hardly visible by the eye. The top of the plungers are influenced by compressible spring means, which forces the plungers down against the chocolate mass and secures that when the holding device are lowered to a certain position, then are all plungers pressed down to complete contact with the mass and complete filling of the enclosures being pressed, whatever the deviations between the deposited volumes of the chocolate lumps on the conveyor web may be.